The present invention relates to the technology of integrated circuit design, and more specifically, relates to a method and apparatus for enhancing integrated circuit noise performance.
The development of integrated circuit manufacturing process results in an increasingly high chip density, while coupling noise between wires also becomes increasingly significant. The coupling noise will generate a coupling delta delay in wires, thereby causing damage to signal time sequence.
Generally, the longer the common portion between two parallel wires, the more significant the coupling noise is between the two wires. It would be easily understood that when the lengths of two wires are relatively long, their common portion is also usually long. The coupling noise between wires is also related to the distance between wires. The larger the distance is, the smaller the coupling noise is. During wiring, a size of a target region and a number of wires that need to be arranged or routed in that target region is usually fixed. Typically, the channels or tracks available for arranging wires in the target region are also fixed. One proposed solution to reduce coupling noise may include arranging two long wires on channels spaced as far apart as possible. For example, short wires are inserted between two long wires, or blank channels are inserted between long wires.
In a target region, a number of wires that need to be arranged might be approximate to a number of channels in the target region. Therefore, it may not be possible to insert short wires or blank channels between long wires in a particular target region due to a lack of available channels.